In recent years, in a wireless communication system in which terminals and wireless base stations are connected to a network, a heterogeneous network has been examined (for example, see NPL 1 to NPL 3). NPL 1 to NPL 3 describe a technology (C/U splitting) in which the base stations are split into the base station that uses a control signal (C-plane) and the base station that uses a data signal (U-plane) in the heterogeneous network.